Defence giant BAE Systems is in talks with the Government of Oman to supply a number of Typhoon fighter aircraft, which would be delivered within three years of a contract being signed.
The aircraft would be built at BAE's site in Warton, near Preston in Lancashire, where hundreds of job losses were announced last year under cuts sparked by a slowdown in production.
The company said it had mitigated 900 of the compulsory redundancies across Warton and another site at nearby Samlesbury, so out of the 1,408 potential redundancies, around 500 will be compulsory.
Officials said today's announcement will not save the jobs, although it will have an impact on the supply chain.
A spokesman said: "BAE Systems welcomes the release of a Request for Proposals (RFP) for the supply and support of Typhoon fighter aircraft for the Royal Air Force of Oman.
"This news underpins the long-standing defence and security relationship between Oman and the United Kingdom and between the armed forces in Oman and BAE Systems, a major supplier of equipment and services to the Sultanate."
Contractual negotiations are due to begin shortly, with BAE expecting it to involve 12 aircraft, to be delivered within 36 months from contract signature.
BAE is undergoing a review of its UK business to reduce costs in anticipation of future orders and to ensure efficiency and effectiveness so it can compete in growing export markets where there is a commitment to defence procurement.
The review of the warship business has raised fears of job losses at sites including the historic Portsmouth dockyard.
BAE said: "As part of our business planning activity, we are reviewing how best to retain the capability to deliver and support complex warships in the UK in the future, in line with our commitments under the Terms of Business Agreement signed in 2009.
"This work is on-going and we will keep our employees and trade union representatives fully informed as it progresses."
A Government spokesman said: "The UK Government welcomes the Government of Oman's request for a proposal from BAE Systems for the supply and support of Typhoon aircraft.
"This represents an important step towards the contract. Not only is this a further sign of the strong and enduring relationship between the two countries, but it also presents a further opportunity for both governments and respective industries to work together to bring wider economic, training and education benefits to Oman."
The Prospect union said it feared the company has already taken the decision to close its shipbuilding facility in Portsmouth.
Negotiations officer John Ferrett said: "The company have been less than forthcoming with unions on their future plans for UK shipbuilding. We were told that the company was using LEK consultants in October last year, but at no time were we told that the consultants were reviewing which of the company's yards should be closed.
"Clearly, when companies take decisions in this way the employees and their representatives have every right to be suspicious."
Prospect said closure would spell "economic disaster" for the local community at a time when highly skilled jobs were crucial for economic growth.